1. Field of the Invention
The present invention relates to a camera system using a rotary mirror type display apparatus which displays an image via a rotary mirror arranged in front of a monitor, and a display apparatus.
2. Description of the Related Art
The present invention concerns a camera system and a display apparatus, in which a rotary camera type display apparatus displaying an image through a rotary mirror arranged in front of a monitor capable of displaying an image from a camera and a rotary mirror type camera picking-up an image of an object via a rotary mirror arranged in front of the camera. In the following disclosure, as discussion for the prior art, to which the present invention is related, examples of two optical and electronic periscopes, one rotary mirror type camera, and one periscope type display apparatus will be discussed.
[Optical Periscope]
An optical periscope is a periscope operated optically without using an electronic equipment, such as a camera and a monitor and has a construction as illustrated in FIG. 27. A user may see an object in a finder through two mirrors fixed to a casing. Also, a direction to see is variable by rotating the casing. As illustrated in FIG. 27, electronic equipments which require wiring for power supply and signal transmission, are not contained in the casing and is constructed with optical parts. Therefore, the casing can be rotated over 360° endless manner and can vary the direction to view over 360°. Therefore, as mounted in submarine, condition on the water can be viewed from under the sea. In the alternative, it may be used to observe an opposite side sight over a high fence. Furthermore, since an absolute direction of the user looking into the periscope always matches with an absolute direction viewed across the periscope to permit observation over 360° in visceral manner.
[Electronic Periscope]
An electronic periscope is constructed with a combination of a camera rigidly secured on a universal head and a periscope type display Apparatus rotating the monitor per se which displays an image from the camera. The construction of the electronic periscope is illustrated in FIG. 28.
In the shown prior art, the electronic periscope is constructed with a combination of a rotary universal head type camera 400 and a periscope type display apparatus 300. The rotary universal head type camera 400 is constructed with a camera 401, a motor 203 driving the camera 401 to rotate via a gear 402 on the basis of a control signal of a control circuit 208, an encoder 204 and an origin sensor for detecting an angular position and an origin position about vertical line with respect to a floor or a ground surface where the camera is placed, and the control circuit 208 for controlling revolution of the motor 203. The periscope type display apparatus is constructed with a gear 302 rigidly secured on a casing 110, a support 107 fixed to the gear 302, a monitor supported by the support 107 and displaying an image signal transmitted from the camera 401, a finder 108 provided on the casing for permitting the user to observe the monitor 301, a gear for transmitting rotation of the gear 302 to an encoder 104, the encoder 104 and an origin sensor 105 for detecting the angular position about the vertical line with respect to the floor or the ground surface, on which the user stands, a handle 109 to be gripped by the user upon rotating the casing.
Next, operation of the foregoing prior art will be discussed. When the user rotates the casing 110 with observing the monitor 301 as looking into the finder 108, the encoder 104 and the origin sensor 105 detects the angular position of the casing via the gear 302 to feed an angle signal A and an origin signal A indicative of detection of the origin, to the control circuit 208. The control circuit 208 drives the camera 401 to rotate on the basis of the angle signal A and the origin signal A and an angle signal B indicative of angular position of the camera 401 and an origin signal B. Revolution of the motor 203 is transmitted to the camera 401 via the gear 402 to drive the camera 401 to rotate. As a method to establish correspondence between the angular position of the casing 110 and the angular position of the camera 401, for example, there is a method to match an orientation (north, south, east and west) of the user looking into the finder 108 and an orientation of the camera 401, namely to establish correspondence so that the absolute orientations become the same. The image data picked-up by the camera 401 is fed to the monitor 301 as an image signal and thus displayed.
As set forth above, the user may orient the camera 401 to the desired direction to monitor by rotating the casing 101. At the same time, the image from the camera can be seen on the monitor 301 across the finder 108. Namely, it becomes possible to monitor all direction over 360° from the site where the rotary universal head type camera 400 on the site where the periscope type display apparatus 300 is installed. Furthermore, similarly to the optical periscope, by matching the absolute angles of the orientation of the user and the orientation of the camera or by matching relative angular displacement, identification of orientation and change of direction can be done visceral manner.
[Camera Control System as Combination of Rotary Mirror Type Camera and Normal Monitor]
A construction of a camera control system, in which a rotary mirror type camera and a normal monitor, is illustrated in FIG. 29.
The conventional camera control system illustrated in FIG. 29 is constructed with a rotary mirror type camera 200, image conversion means 502 for image conversion of an image from the camera 201, a monitor 501 for displaying the image processed for conversion by the image conversion means 502 and a rotary mirror operating means 503 for feeding an operation signal of operation of the user to the control circuit 208. The camera 201 is constructed with the camera 201, a mirror 202 arranged in front of the camera 201 at an angle about 45° with respect to a light axis, a motor 203 driving the mirror 202 for rotation about the light axis of the camera 201, the encoder 204 and the origin sensor 205 detecting the angular position of the mirror 202 about the light axis of the camera and the origin position, and the control circuit 208 for controlling revolution of the motor 203.
Operation of the prior art shown in FIG. 29 will be discussed. When the user operates the rotary mirror operating means 503, the operation signal indicative of the content of control is fed to the control circuit 208. As the rotary mirror operating means 503, lever, dial, cursor key and so forth are applicable, for example. When the cursor key 208 is applied, it may be required to rotate the mirror toward right and left by a right arrow key and left arrow key. The control circuit 208 controls the motor 203 on the basis of the operation signal from the rotary mirror operating means 503, the angle signal B from the encoder, the origin signal B from the origin sensor 205 to realize rotation of mirror depending upon operation by the user. The image thus input to the camera 201 via the mirror 202 driven to rotate, is fed to the image conversion means 502 as the image signal.
The process of image conversion in the image conversion means 502 will be discussed with reference to FIG. 30. The camera 201 does not vary relative angle with respect to the floor or the ground surface, on which the rotary mirror type camera 200 is fixed, and only mirror 202 is relatively rotated. Therefore, the image input to the camera 201 via the mirror 202 which is rotated, is rotated in vertical direction of the object (upper half of FIG. 30: arrow represents up and down direction of the object, and the arrow points upward direction). Namely, the vertical direction of the object is rotated in the image associating with rotation of the mirror 202.
The image conversion means 502 converts the rotation converts the image to place upward direction of the object to upward direction of the arrow as the converted image which is illustrated. However, in this manner, the user may see rotated rectangular image.
On the other hand, when the mirror 202 is placed at various angle, and if the converted images are overlaid in coaxial fashion, there are circle C2 constantly enclosing the overall screen, a circle C1 constantly presenting the image, a rectangle S1 touching internally with the circle C1 and a rectangle S2 touching externally to the circle C2 (lower half of FIG. 30). Accordingly, for example, by clipping a region corresponding to the circle C1 in the converted image and displaying on the monitor 501, the user may constantly see the image of the same shape (circle in this case).
In the prior art as set forth above, the user may monitor the image of the desired direction on the monitor 501 by rotating the mirror 202 by operating the rotary mirror operating means 503.
[Japanese Unexamined Patent Publication No. Heisei 9-292827 “Rotary Type Image Viewing Apparatus”]
As the prior art relating to the periscope type display apparatus, there is a “rotary type image viewing apparatus” disclosed in Japanese Unexamined Patent Publication No. Heisei 9-292827.
FIG. 31 is an illustration showing a construction of the conventional rotary type image viewing apparatus. For facilitating understanding correspondence with the embodiments of the present invention, respective components illustrated in Japanese Unexamined Patent Publication No. Heisei 9-292827 will be identified by names and reference numerals different from those used in the publication. However, the following discussion for the above-identified publication will not change significance of the disclosure.
In the shown prior art, the rotary type image viewing apparatus is constructed with the periscope type display apparatus 300, image storage means 601 for storing the overall image for displaying on the monitor 301 and image extracting means 602 for detecting angular position of the casing on the basis of the signals from the encoder 104 and the origin sensor 105 and extracting the image to be displayed from the overall image stored in the image storage means 601 depending upon the angular position for displaying on the monitor. The periscope type display apparatus is constructed with the gear 302 fixed to the casing 110, the monitor 301 supported by the support 107, the finder 108 provided in the casing 110 so that the user may view the monitor 301, the gear 302 for transmitting rotation of the gear 302 to the encoder 104, the encoder 104 and the origin sensor 105 for detecting the angular position about the vertical line with respect to the floor or the ground surface where the user stands and the origin position, the handle 109 to be gripped by the user when the casing 110 is rotated.
Operation of the prior art will be discussed. When the user rotates the casing with gripping the handle 109 with looking into the monitor 301 through the finder 108, the encoder 104 and the origin sensor 105 detects the angular position of the casing 110 via the gear 302 to feed the angle signal A and the origin signal A indicative of detection of the origin to the image extracting means 602. The image extracting means 602 extracts the image to be displayed on the monitor 301 in the overall image stored in the image storage means 601. The image extracted by the image extracting means 602 is fed to the monitor 301 for displaying.
FIG. 32 is an illustration showing a manner of extraction of the image to be displayed on the monitor 301 by the image extracting means 602 from the overall image stored in the image storage means 601. When an image as viewed from inside of a Penguin breeding space in an aquarium virtually, Panoramic image as shown (upper half in FIG. 32) may be stored in the image storage means 601. Lateral direction of the Panoramic image corresponds to the direction which the user desire to view, namely the angular position of the casing 110, by the shown prior art of the rotary type image viewing apparatus. The direction to be viewed extends over all directions from 0° to 360°. If the user rotates the casing 110 over an angle α from a reference position, the image extracting means extracts the image of the portion corresponding to the angle α from the overall Panoramic image (lower half of FIG. 32) to feed to the monitor 310.
[Rotary Type Image Viewing Apparatus Discussed as Prior Art in Japanese Unexamined Patent Publication No. Heisei 9-292827]
As the prior art relating to the rotary type image viewing apparatus, discussion will also be given for the rotary type image viewing apparatus (corresponding to FIGS. 3 and 4 of Japanese Unexamined Patent Publication No. Heisei 9-292827) which has been disclosed as prior art in the above-identified publication, and which is shown in FIG. 33. Again, names and reference numerals different from those used in the publication are used for facilitating understanding of correspondence with the embodiments of the present invention. However, the following discussion for the above-identified publication will not change significance of the disclosure.
The shown prior art is constructed with a periscope type display apparatus 700 and an image generating means 600A. The periscope type display apparatus 700 includes a ring gear 106 fixed to the casing 110, the support 107, a monitor 701 supported by the support 107, the mirror 102 supported on the support 107 at an angle approximately 45° with respect to a straight line extending frontwardly through substantially center of the monitor 101 perpendicular to the display screen 101, a finder 108 for looking into the image on the monitor via the mirror 102, the encoder 104 and origin sensor 105 for detecting the angular position about the vertical line with respect to the floor or the ground surface where the user stands and the origin position, the handle 109 to be gripped by the user when the casing 110 is rotated. The image generating means includes an image storage means 601 storing overall image for displaying on the monitor 701, image extracting means 602 for detecting angular position of the casing on the basis of the signals from the encoder 104 and the origin sensor 105 and extracting the image to be displayed from the overall image stored in the image storage means 601 depending upon the angular position for displaying on the monitor and image conversion means 603A for performing conversion so that the image may be correctly displayed with respect to left and right and up and down on the periscope type display apparatus.
Operation of the shown prior art will be discussed.
The user rotates the casing 110 with gripping the handle 109 with observing the image on the monitor 301 reflected by the mirror 102 as looking into the finder 108. Then, the encoder 104 and the origin sensor 105 detects angular position of the casing 110 via the gear 302 to feed the angle signal A and the origin signal A indicative of the origin detection to the image extracting means 602. The image extracting means 602 extracts the image to be displayed on the monitor 701 from the overall image stored in the image storage means 601 on the basis of the angle signal A and the origin signal A to feed to the image conversion means 603A. The image conversion means 603A converts the image fed from the image extracting means 602 by inverting in up side down manner with taking a horizontal line extending through the center of the image as symmetry axis to feed to the monitor 701. The image displayed on the monitor 701 is provided to the user from the finder 108 via the mirror 102. In the image conversion means 603A, a reason for inverting the image in up side down manner is that the display image on the monitor 701 is inverted up side down as output to the finder 108 as reflected by the mirror 102, as shown in FIG. 34.
FIG. 35 is an illustration showing a manner of image conversion process, in which the image to be displayed on the monitor is extracted by the image extracting means 602 from the overall image stored in the image storage means 601 and is processed for image conversion by the image conversion means 603A. Up to image extraction, the process is the same as those discussed with reference to FIG. 32 (upper and intermediate portions of FIG. 35). In the shown prior art, the extracted image is inverted in up-side-down manner by the image converting means 6093A.
However, the foregoing four prior arts encounter the following drawbacks.
[Problem of Optical Periscope]
Since the reflection light from the object is optically led to the finder, it is the most feasible way to extend an optical path directly above the site where the user is located to see the object from the higher position than the user. A typical example of this is the periscope employed in the submarine. Accordingly, for observing the object from the position distanced in horizontal direction instead of directly above the user, a complicated optical system is required and is significantly difficult or even impossible to realize in certain case.
[Problem of Electronic Periscope]
By employing the electronic periscope, the image of the distal site which has been difficult to monitor by the optical periscope can be monitored. Namely, by installing a rotary universal head type camera at the distal site, the camera is driven to control the angular position by the periscope type display apparatus for monitoring the obtained image. However, in case of the rotatable universal head type camera, whole camera or the entire monitor in case of the periscope type display apparatus are rotated. The camera and monitor are relatively bulky and heavy. Accordingly, both of the rotatable universal head type camera and the periscope type display apparatus may have bulky and heavy rotary portions. This results is increasing of size of motor and requiring large current in the rotary universal head type camera on one hand and increasing size and weight of the casing to be operated by the user to rotate in the periscope type display apparatus on the other hand.
Furthermore, for the monitor and the camera, electrical connection is inherent. When the periscope type display apparatus is desired to be rotated in endless manner, connection between the rotating portion and the rotated portion has to be connected through a slip ring.
[Problem in Camera Control System Combined with Rotary Mirror Type Camera and Normal Monitor]
The rotary mirror type camera has no electrical connection and can obtain wide vision image by rotating only relative light weight mirror to contribute for downsizing of the apparatus. However, since the camera is fixed and only mirror is rotated, the obtained image is rotated in vertical direction. Accordingly, upon displaying the image on the normal monitor, it is required to display the obtained image after rotational conversion process.
[Problem of “Rotary Image Viewing Apparatus” as Disclosed in Japanese Unexamined Patent Publication No. Heisei 9-292827]
Even in this prior art discussion with reference to FIGS. 31 and 33, there is an electrical connection and has a relatively heavy monitor which is rigidly secured on the periscope type casing operated by the user. Therefore, the user has to rotate the heavy casing. Furthermore, for rotating the casing in an endless manner, a slip ring has to be employed inherently.